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Sync Multiple Devices With One User's Mailbox Using Exchange ActiveSync

    Question

  • Hello!  I have a user who is interested in syncing her new iPad with our Exchange 2003 server using Exchange ActiveSync (EAS).  However, this user is already syncing her iPhone with our Exchange server.  A few questions:

    1. I've read that sync problems can occur if multiple devices attempt to sync to a user's mailbox via EAS.  Is this still true?

    2. Do newer versions of Exchange resolve this limitation?  If not, is support for this planned in an update or future Exchange version?

    3. What are my alternatives?  Unfortunately, IMAP will only get the user's email, and I will also need to sync the user's calendar and contacts.

    Thanks!

    Wednesday, April 28, 2010 5:53 AM

Answers

  • It's no problem syncing multiple devices with one user account over EAS. There's obviously some theoretical limit to how many devices you can have, but I usually have 2-3 different devices in sync at the same time without any conflicts between them.
    • Proposed as answer by Elvis Wei Friday, April 30, 2010 2:32 AM
    • Marked as answer by Aakash Shah Sunday, May 02, 2010 12:07 AM
    Thursday, April 29, 2010 7:05 AM

All replies

  • It's no problem syncing multiple devices with one user account over EAS. There's obviously some theoretical limit to how many devices you can have, but I usually have 2-3 different devices in sync at the same time without any conflicts between them.
    • Proposed as answer by Elvis Wei Friday, April 30, 2010 2:32 AM
    • Marked as answer by Aakash Shah Sunday, May 02, 2010 12:07 AM
    Thursday, April 29, 2010 7:05 AM
  • Hi Askash,

     

    There is no problem for two devices. My colleague even use 10 devices work with one account without any problem.

     

    Thanks,

     

    Elvis  

    Friday, April 30, 2010 2:37 AM
  • Big deal.  My colleagues use 20 devices!
    --
    Ed Crowley MVP
    "There are seldom good technological solutions to behavioral problems."
    .
    "Elvis Wei -MSFT" wrote in message news:9235a00c-2950-4389-9738-76df3c424d74...

    Hi Askash,

     

    There is no problem for two devices. My colleague even use 10 devices work with one account without any problem.

     

    Thanks,

     

    Elvis  


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Friday, April 30, 2010 3:35 AM
  • Hello!  Thank you all for the replies.  I'm curious what Exchange server version everyone is using with the clients who have multiple devices connected via EAS to their mailbox?  Is this Exchange 2003, or something newer?

    The reason I ask is because I posted a similar question about two years ago, and Elvis Wei mentioned that this was not recommended:

    "I do not recommend to use two mobile device sync with one user account. If two devices were done different operations, it can cause data sync issue or even lost data."
    http://social.technet.microsoft.com/Forums/en-US/exchangesvrclients/thread/6954ddf9-0849-4ccb-b572-29edfc00d4e3

    I'm curious to know what has changed since then?  Was a patch released for Exchange to support this?  Or, is this only supported on newer versions of Exchange?  Or, has EAS been upgraded to prevent any problems?

    Thanks!

    • Proposed as answer by Gareth Fletcher Thursday, September 13, 2012 11:24 PM
    • Unproposed as answer by Gareth Fletcher Thursday, September 13, 2012 11:24 PM
    Friday, April 30, 2010 6:18 AM
  • I have been doing this since Exchange 2003 SP2 (since SP2 introduced DirectPush). All releases after that have been working smoothly syncing as many devices as I can throw at it. Exchange maintains separate sync state pr client (actually the client maintains the state, but the server provides some assistance). Theoretically you can get out of sync if you try to - like deleting mail on one device and adding on another. But even then I think it would require a lot of bad luck to run into problems.
    Friday, April 30, 2010 7:00 AM
  • Andreas: Awesome!  Thanks for the information. I'm glad to hear this and I'm sure my user will be happy too!

    All: So that I can present this to management, can one of the MS Exchange folks confirm this too?

    Thanks!

    Friday, April 30, 2010 4:01 PM
  • HI Aakash,

     

    Sorry for the confusion. I think my former understanding two years ago is incorrect. Use multiple devices against one account is OK.

     

    Thanks,

     

    Elvis

    Monday, May 03, 2010 2:49 AM
  • Elvis: Thanks for the clarification.  I've also updated the 2008 thread to reflect that this is no longer a problem in case anyone comes across it.

    Monday, May 03, 2010 3:25 AM
  • Hi Elvis,

    We've been observing Inbox, Contacts, Calendar failing to Sync with error 3 (Bad sync key) and the Account mailboxes failing with FolderSync error 9 (Bad sync key). This is happening on a test account which around 20 devices are connected.

    The only non typical condition on the account is that the users keep adding, syncing and deleting email accounts with high frequency (causing the sync to happen way more often than the average accounts). 

    The failures has never been observed when just one device is connected.

    Both our corporate and gmail (m.google.com) exchange servers are failing on the same scenario.

     

    Is it reasonable to correlate those failures with multiple clients syncing the same account simultaneously?  Is there a solution for this condition?

     

    thanks,

    Fernando

     

     

    Saturday, February 26, 2011 3:25 AM
  • We are using Exchange 2007 and users are experiencing multiple device sync issues.  There are no errors but if a user has an iPhone and an iPad, clearing the Read flag on one will clear it on Exchange but not on the other device.  We have attempted to delete devices in ActiveSync and reinitialize but the problem persists.

     

    Thanks,

    Don

    Thursday, June 30, 2011 3:58 PM
  • Is it possible to set a limit on the number of possible devices?

    We are slowly allowing devices to connect directly via EAS, as we need to control data.  I was asked by our corporate compliance if it was possible to limit a mailbox to one specific device at a time.

    Regards,

    Troy

     

    Friday, July 22, 2011 10:03 PM
  • Is it possible to set a limit on the number of possible devices?

    We are slowly allowing devices to connect directly via EAS, as we need to control data.  I was asked by our corporate compliance if it was possible to limit a mailbox to one specific device at a time.

    Regards,

    Troy

     


    If you're running Exchange 2010 Service Pack 1 a single user is by default limited to 10 devices. If you try to set up device number 11 you will be informed you've gone over the quota. The limit can easily be changed to a lower or higher number.

    The user is however able to remove devices if they have access to OWA so they'd be able to remove old devices before setting up their new device again, but if the compliancy requirement is only 1 device syncing at a time the goal is met.

    If you're running an older version of Exchange you would have to resort to third-party software to achieve it.

    Saturday, July 23, 2011 3:41 PM
  • Exchange 2010 with extremely high transaction log growth
    One of my user had setup two mobile iPhone and iPad devices to activeSync with Exchange 2010 mailbox.  That was the cause in my case with extremely high transaction log growth.  Once we identified and removed one of the device log growth issue stabilized.
    Thursday, March 22, 2012 9:10 PM
  • We have also seen large log file growth when two or more idevices connect to the same mailbox.  Exchange 2003 SP2.

    No sync problems are occuring just large weblogs.

    Friday, June 01, 2012 6:57 PM